Which of the following accounts is not included in the quick ratio computation? 1-Cash 2-Marketable securities 3- A/R 4- Prepaid rent 5-A/P

Quick Ratio is calculating based on the current assets which can be convertible into liquid cash immediately. Generally Inventories is considered as non-liquid asset, but this is not available in your options.

The prepaid rent can be the answer if it cannot be convert into cash immediately, however if the scenario permit to convert this amount into cash immediately then it has be a part of Quick Ratio calculation. 

Prepaid rent 

My answer is C. Prepaid rent.